Improvement in electric signal-boxes



E; J.. FROST.

ELECTRIC SIGNAL-Box.'

No.172,415. 'Paiented .an. 18, 1876.

UNITED STATES PATENT EEIGE.

EDWARD J. FROST, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT lN ELECTRIC SIGNAL-BOXES.l

Specification formingpart of Letters Patent No. 172,4] 5, dated January 18, 1876; application filled December 15, 1875.

To all whom it may concern:

Be it known that I, EDWARD J. FROST. of the city of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Electrical SignalBoXes5 and I do hereby declare that the following is a full, clear, and exact description thereof', which will ena-` ble others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawing, land to the letters of reference marked thereon, which form a part of this specication.

The object of my invention is to furnish a box certain and reliable in its operations, and capable only of being usedwhen the line is in such condition-i. c.,not in use by others than the one wishing to use a certain boxthat its use will lead to no confusion; and to this endit consists in those devices and combinations hereinafter fully set forth and view, and Figs. 3, 4, and 5 are views of de' tails.

ais the main driving-shaft, to which is attached the master-wheel A, a drivingspring, (not necessary to be shown here,) apawl and ratchet, c c', and a crank and handle, B, all of ordinary construction, and operating a train of gearing, C C', in the usual manner. The train is provided with an` anchor and escape-wheel, C G, or equivalent devices, for regulating its movements. One of the wheels C of the train is arranged so as to form, of it self, the circuit maker and breaker for controlling the circuit to give a signal. 'As shown in Fig. 4E, this wheel is composed of two halves, c and d, united, c -being made of hard rubber or other insulating material, and el-ot metal. A part of the teeth of d is cut away, so that the metal portion of d shall not a-t all times engage with the metal wheel C', but shall only engage therewith at the times necessary to complete the circuit for sending the signal.

By this construction I am enabled to dispense with the ordinary circuit-wheel and spring and utilize one of the wheels of the train therefor.

The wheel G is mounted on an insulated bearing, and one end of the line-wire is put in connection with the shaft of the wheel, the other end being connected to the frame of the machine.

It is evident that the'wheel need not necessarily be divided lengthwise, but that it may be made of alternate conducting and non-conducting portions, the teeth being cut across the entire width of the face.

Where several boxes of this general character and purpose are used upon one circuit it is desirable that there should bevcombined vtherewith some means for preventing two or more of them being used or turned in simultaneously, so that there may be no interference of signals. This I accomplish in the fol lowing manner: Below the train of gearing is journaled a ratchet-wheel, D, provided with a spring, s, which holds it normally in the position shown in Fig. 1, a pin, r, passing through the shaft p 'of the wheel, limiting its motion in either direction by taking against the shaft It. This wheel is furnished with a knob, E', for rotating it, and arm E projects from the shaft. Normally this arm, as shown in Fig. l, is in the path of the handle B of the alarm or signal mechanism, the teeth on the ratchetwheel c being so proportioned that the movement ofthe crank and handle B, before strik ing the arm E, will affect no winding up of the mechanism. This necessitates the removal of the arm E. Ordinarily this would be prevented bythe pawl on the end of the armature-lever F of the electro-magnet E M. This lever ispivoted 011 the block g, and is provided with adjusting-screws f f for limiting its motions. At the other extreme of the shaft p of the arm E is a switch-arm, G, normally resting upon a switch-button, 6, from which a wire, 4, leads direct to binding-post 4, so that normally the electro-magnet E M is i shunted out of the circuit, the circuit being 2 l www' by post l, wire 3, wheel C, frame of instrument, button 6, and wire 4to post 4.

The position ofthe teeth in wheel D, and of the pawl, are so arranged in relation to each other' that the shaftp may have normallya slight motion, suthcient to carry the switcharm G from button 6, and so break the shuntcircuit described. This first movement, then, in attempting to move arm' E out of the path of winding-arm B, causes the circuit to be thrown through the magnet, via 1, 3, C, frame, 3, E M, to 2. Now, if the circuit be -not in use, but closed, (as it will be if unused,) the magnet E M attracts its armature, and the arm E may be removed entirely from the path of B. In so moving it the switch-arm G has been brought in contact with button 7, establishing a new shunt-circuit via l, 3, C, frame, s, G, 7, 5, 2, again cutting out the magnet E M and lessening the resistance in the circuit. The arm B may now be turned to wind the spring, which, upon its recoil, gives motion to the train and causes the desired signal to'vbe transmitted.

If, however, upon the first movement of E, and the consequent throwing of the circuit through E M, the line be in use, and the lcircuit interrupted, the magnet E M will not attract its armature ;v hence, the pawl will prevent the arm E from being removed from the'path of the arm B, thisprevention lasting during the continuance of such use of the circuit, thus preventing any interference of signals.

,When the circuit is free for the user of any box, the arm E has been turned in Vthe direction of the arrow, as before described, and the switch-arm G has held contact with button 7 during the use of the box. It is necessary, however, after the signal is sent, that the parts should be restored to their normal position. This I accomplish as follows: Zis a latch, pivoted at Z to a suitable base-plate.

Rising from Z is arod, h, provided with a spring, t', for holding` it in onenormal position. 0n the Linder face of Wheel D is a pin,

n, in whose path lies the outer end of latch Z hence, when wheel D is rotated in the direction jecting from shaft a of crank or winding arm B. When, however, the shaft be rotated in the direction of the arrow, Fig. 3, in winding up the box, thc pin b takes upon and depresses arm k, so passing it, spring m immediately restoring arm 7c. As the shaft andthe arm B, by the action of the mainspring, are restored to their normal position, the pin b takes under and-lifts the arm c,wl1iclrcar ries with it the rod h, which, in turn, lifts latch Z, allowing the wheel D to be restored to its normal position by the action of its spring s.

It is evident, where a box is provided With a door, usually kept closed or locked, that the device E E and attached parts may be arranged so that the arm E shall be in the path of the key or other unlocking device. When the devices are so arranged it will be impossible to open the door while the line is in use.

It will be seen, from the foregoing description of my improved box and its operation, that great certainty of action is secured, and the ends sought fully accomplished, and that by only a momentary use of the electro-magnet, and a momentary increase of the resistance in the circuit.

Having thus described my invention, what I claim, and desire to secure by Letters Patent 1s l. The combination, with the signal mechanism of a signal-box, of a detent, a locking mechanism, and one or more shunt-circuits,

the locking mechanism being brought into action, when necessary, automatically, upon a shunt-circuit being broken by the attempted 4 and Vin its movements the circuits of an electroa and r, and spring s, of arm E, operating as.

a detent to signaling mechanism, and requiring locking mechanism to be put in condition for operation before the signaling-train can be operated, substantially as and for the purpose set for-th.

7. The combination, with an electro-magnet controlling locking mechanism, of the shunt circuits 4 and 5, controlled by detent E, substantially as and for the purpose set forth.

8. The combination, with the detent, of the In testimony that I claim the foregoing as latch l, rod h, arm 7e, and pin b, substantially my own I affix my signature in presence of as and for the purpose set forth. two witnesses.

9. In an automatic signal-box, a gear-Wheel constructed of insulating and conducting por'- EDWARD J' FROST' tions, so that, while acting as one Wheel of a Witnesses:

train, it shall also act as a circuit-controller, JAMES C. FAIRBAIRN, substantially as set forth. JOSEPH LALLON. 

